Plastic blow-molded containers are commonly used for food packaging products. Many food and beverage products are sold to the consuming public in wide mouth jar-like blow-molded containers. These containers can be made from polyethylene terephythalate or other suitable plastic resins in a range of sizes. The empty blow-molded containers can be filled with food and/or beverage products at a fill site utilizing automated fill equipment.
For example, manufacture of such plastic blow-molded containers can include initially forming plastic resin into a preform, which may be provided by injection molding. Typically, the preform includes a mouth and a generally tubular body that terminates in a closed end. Prior to being formed into containers, preforms are softened and transferred into a mold cavity configured in the shape of a selected container. In the mold cavity, the preforms are blow-molded or stretch blow-molded and expanded into the selected container.
Such plastic blow-molded containers may be produced on single stage injection mold equipment. The single stage blow molding process combines the injection molding of the preform and blowing of the container into one machine. This machine has an extruder that melts resin pellets and injects the molten resin into a mold to create the preform. The preform is transferred to a blow station to form the container and removed from the machine. In some cases, the plastic blow-molded containers are produced with two-stage equipment. The two-stage equipment makes preforms in an injection molding machine and then reheats and blows the preforms into selected containers in a separate blowing machine. This disclosure describes an improvement over these prior art technologies.